18. Set Multiple Bits in 8-bit Register

#include <stdio.h>
#include <stdint.h>
#include <cmath>

uint8_t set_range(uint8_t reg, uint8_t start, uint8_t end) {
    // Your code here
    uint8_t masklen = end - start +1;
    uint8_t mask = 0;

    for (int i = 0 ; i < masklen ; i++) {
        mask += pow(2 , i);
    }

    reg |= (mask << start);     
    return reg;
}

int main() {
    uint8_t reg, start, end;
    scanf("%hhu %hhu %hhu", &reg, &start, &end);
    printf("%u", set_range(reg, start, end));
    return 0;
}